In arthroscopic and endoscopic surgery, surgical knots are tied and passed through a cannula. This procedure presents the surgeon with the task of loading the suture into, or through, a knot manipulator and "pushing" or "pulling" the knot through the cannula. This loading process can be likened to the threading of a needle and can be difficult for the surgeon when the suture is braided or when he is working with gloved hands.
Several knot pusher type devices are known. These knot pusher devices are designed to push suture knots which have been tied extracorporeally or outside of the body during a surgical procedure toward the tissue to be sutured. Many of these devices then function to cut the suture strands once the suture knot has been tied in its proper position. For example, U.S. Pat. No. 5,403,330 issued to Tuason discloses an improved laparoscopic suture knot pusher having an elongated, slender shaft having one end which serves as a handle and another end which serves as a guide for pushing surgical knots forward toward their intended site. The knot pusher guide end is slightly convexed and includes three hollowed-out spaces for receiving and engaging the throws and strands from throw knots that are delivered through a trocar. One of the hollowed-out spaces is a slot that runs across a midsection of a slightly convexed surface that has a spheroidal shaped configuration at the distal end of the shaft.
Another example of a surgical knot pusher is described in U.S. Pat. No. 5,752,964 issued to Mericle. The Mericle patent discloses a surgical knot pusher for pushing a suture knot along a suture strand. The Mericle surgical knot pusher includes an elongated tube with a flattened tip formed on the distal end of the tube. The flattened tip is slotted and provided with an eyelet which restricts the suture and prevents it from falling out of the flattened tip. The suture is easily positioned without threading by pushing the slot on the tip against the suture, thereby forcing the suture through the slot and into the eyelet. A movable rod member having a cutting blade is also affixed to the inside of the distal end of the elongated shaft to provide a cutting device for the suture.
A method and apparatus for placing and tying a knot is also disclosed as a knot pusher assembly in U.S. Pat. No. 5,549,618 issued to Fleenor et al. This apparatus includes a suture knot pusher tube having a distal end slot and an inner concentric tube positioned within the pusher tube where the inner concentric tube also has a distal end slot. The pusher tube and inner concentric tube are movable with respect to one another such that their distal end slots may be aligned or unaligned. The suture can be cut by placing it into the aligned distal slots and then misaligning those slots by moving the pusher tube and inner concentric tube with respect to one another. Further, a knot puller instrument for aiding a surgeon in tying surgical knots is disclosed in U.S. Pat. No. 5,693,061 issued to Pierce et al. The apparatus includes an elongated main body having a linear central longitudinal axis and proximal and distal end portions. The proximal end provides a handle for gripping and the distal end includes a pair of spaced-apart appendages that are positioned to hold a length of suture between them at a transverse, concavely shaped bridge portion. A space between the appendages is formed by suspending one appendage free from the instrument body and connecting the appendage only to the bridge member. During use, the surgeon engages a length of suture with the transverse curved bridge connector by placing it between the two appendages. The surgeon then forces the main body in a desired direction to pull one of the suture-free ends away from the knot being formed, thereby applying tension that helps to tie a knot.
Although several of the previously described devices eliminate the need for threading an eyelet when forming and tying surgical knots during endoscopic and laparoscopic surgery, there is a need for a surgical knot manipulator which allows the suture to be slipped onto the device at any point in the sliding of the throw of a knot.